We present a survey of medium-scale traveling ionospheric disturbances (MSTIDs)
observed by a Super Dual Auroral Radar Network HF radar located in the Falkland
Islands between May 2010 and April 2011. The radar has a ﬁeld of view that overlooks
the Antarctic Peninsula, a known hot spot of gravity wave activity. We present
observations of radar ground-backscatter data, in which the signatures of MSTIDs are
manifested as structured enhancements in echo power. Observed periods were in the
range 30–80 min, corresponding to frequencies of 0.2–0.6 mHz. Wavelengths were
generally in the range 200–800 km and phase speeds in the range 100–300 m s[superscript –1]. These
values are within the ranges typically associated with medium-scale gravity waves. We
ﬁnd a primary population of northward (equatorward) propagating MSTIDs, which
demonstrate an association with enhanced solar wind-magnetosphere coupling and a
smaller, westward propagating population, that could be associated with atmospheric
gravity waves excited by winds over the Andean and Antarctic Peninsula mountains or by
the high winds of the Antarctic Polar Vortex.